fix(navigation, pairing): update route handling and invite screen layout

app/src/main/java/com/couplesconnect/app/core/navigation/AppNavigation.kt

@@ -174,7 +174,10 @@ fun AppNavigation(
 
             // Pairing
             composable(route = AppRoute.CREATE_INVITE) {
-                CreateInviteScreen(onNavigate = navController::navigate)
+                CreateInviteScreen(
+                    onNavigate = navController::navigate,
+                    onBack = { navController.popBackStack() }
+                )
             }
             composable(route = AppRoute.EMAIL_INVITE) {
                 EmailInviteScreen(onNavigate = navController::navigate)

app/src/main/java/com/couplesconnect/app/ui/pairing/CreateInviteScreen.kt

@@ -1,6 +1,7 @@
 package com.couplesconnect.app.ui.pairing
 
 import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
@@ -14,19 +15,23 @@ import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.filled.ContentCopy
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.Card
 import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
+import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
@@ -43,9 +48,11 @@ import androidx.hilt.navigation.compose.hiltViewModel
 import com.couplesconnect.app.core.navigation.AppRoute
 import kotlinx.coroutines.launch
 
+@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun CreateInviteScreen(
     onNavigate: (String) -> Unit = {},
+    onBack: () -> Unit = {},
     viewModel: CreateInviteViewModel = hiltViewModel()
 ) {
     val state by viewModel.uiState.collectAsState()
@@ -60,7 +67,19 @@ fun CreateInviteScreen(
         state.error?.let { snackbar.showSnackbar(it); viewModel.dismissError() }
     }
 
-    Scaffold(snackbarHost = { SnackbarHost(snackbar) }) { padding ->
+    Scaffold(
+        snackbarHost = { SnackbarHost(snackbar) },
+        topBar = {
+            TopAppBar(
+                title = {},
+                navigationIcon = {
+                    IconButton(onClick = onBack) {
+                        Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = "Back")
+                    }
+                }
+            )
+        }
+    ) { padding ->
         Column(
             modifier = Modifier
                 .fillMaxSize()
@@ -99,16 +118,17 @@ fun CreateInviteScreen(
                     ),
                     elevation = CardDefaults.cardElevation(defaultElevation = 0.dp)
                 ) {
-                    Column(
+                    Box(
-                        modifier = Modifier.padding(24.dp),
+                        modifier = Modifier
-                        horizontalAlignment = Alignment.CenterHorizontally
+                            .fillMaxWidth()
+                            .padding(32.dp),
+                        contentAlignment = Alignment.Center
                     ) {
                         Text(
                             text = state.inviteCode!!.chunked(3).joinToString(" – "),
                             style = MaterialTheme.typography.displaySmall,
                             color = MaterialTheme.colorScheme.onPrimaryContainer,
-                            textAlign = TextAlign.Center,
+                            textAlign = TextAlign.Center
-                            letterSpacing = androidx.compose.ui.unit.TextUnit.Unspecified
                         )
                     }
                 }